This present disclosure relates generally to techniques for performing wellsite operations. More specifically, the present disclosure relates to techniques, such as seals and/or blowout preventers, for sealing wellbores and/or related testing.
Oilfield operations may be performed to locate and gather valuable downhole fluids. Oil rigs are positioned at wellsites, and downhole tools, such as drilling tools, are deployed into the ground to reach subsurface reservoirs. Once the downhole tools form a wellbore to reach a desired reservoir, casings may be cemented into place within the wellbore, and the wellbore completed to initiate production of fluids from the reservoir.
Downhole tubular devices, such as pipes, certain downhole tools, casings, drill pipe, liner, coiled tubing, production tubing, wireline, slickline, or other tubular members positioned in the wellbore, and associated components, such as drill collars, tool joints, drill bits, logging tools, packers, and the like, (referred to as ‘tubulars’ or ‘tubular strings’), may be positioned in the wellbore to enable the passage of subsurface fluids to the surface.
To prevent leakage of subsurface fluids from the wellbore, equipment, such as blow out preventers (BOPs), may be positioned about the wellbore to form a seal to prevent leakage as fluid is brought to the surface. BOPs may have closing mechanism, such as rams or spherical fingers, that may be activated to seal and/or sever a tubular in a wellbore. Some examples of BOPs are provided in U.S. Patent/Application Nos. 2011/0226475; 20110000670; U.S. Pat. Nos. 8,424,607; 7,814,979; and 7,367,396, the entire contents of which are hereby incorporated by reference herein.